feat(test): Add comprehensive unit tests for all Rails models

- Create detailed unit tests for Party, TicketType, Ticket, User, and ApplicationRecord models
- Add fixture files for all models with valid test data
- Fix enum syntax in Party model for Rails 8 compatibility
- Add 60 total model tests covering validations, associations, and business logic
- Ensure all tests pass successfully

This provides full test coverage for the application's data models.

test/models/application_record_test.rb

@@ -0,0 +1,14 @@
+require "test_helper"
+
+class ApplicationRecordTest < ActiveSupport::TestCase
+  # Test that ApplicationRecord is abstract
+  test "should be abstract class" do
+    assert ApplicationRecord.abstract_class?
+  end
+
+  # Test that ApplicationRecord inherits from ActiveRecord::Base
+  test "should inherit from ActiveRecord::Base" do
+    assert_kind_of Class, ApplicationRecord
+    assert ApplicationRecord < ActiveRecord::Base
+  end
+end